1. Technical Field
The present invention relates to a method and a device for filling a container with a liquid maintaining the cleanness of the liquid, and to a liquid container.
2. Related Art
For example, JP-A-2005-186343 discloses a method of filling a liquid chamber unit with a liquid, the liquid chamber unit including a liquid chamber capable of containing a liquid therein and a communication port that secures communication between inside and outside of the liquid chamber. The method includes aspirating air from inside of the liquid chamber through the communication port by using a first suction unit, introducing, by using a liquid injector, the liquid stored in a liquid storage unit into the liquid chamber as cleaning liquid through the communication port, aspirating the cleaning liquid introduced into the liquid chamber through the communication port by using a second suction unit, mixing the cleaning liquid aspirated by the second suction unit and the liquid in the liquid storage unit by using a mixer, and introducing the liquid mixed by the mixer into the liquid chamber by using the liquid injector.
By the liquid filling method according to JP-A-2005-186343, the liquid supplied from the liquid storage unit is introduced into the liquid chamber depressurized by the first suction unit, and the liquid thus introduced is aspirated by using the second suction unit, in the manufacturing process of the liquid chamber unit. Accordingly, dust and air in the liquid chamber and the communication port are discharged together with the liquid. Then the liquid aspirated by the second suction unit is mixed with the liquid in the liquid storage unit by the mixer and introduced into the liquid chamber by the liquid injector, and therefore the aspirated liquid can be utilized as the liquid to be stored in the liquid chamber unit, without being disposed of. Such an arrangement improves the degree of deaeration and cleanness in the liquid chamber unit, and allows the liquid to be efficiently utilized in the manufacturing process of the liquid chamber unit.
To perform the liquid filling method according to JP-A-2005-186343, however, the cleanness of the first and the second suction unit and the liquid injector, through which the liquid passes, has to be secured in advance. The liquid to be actually filled may be employed as the cleaning liquid in order to secure the cleanness in advance, however the liquid used for cleaning is not always reusable. For example, in the case where the cleaning liquid contains an ionic impurity, the liquid may be non-reusable depending on the purpose of use of the liquid. Further, the complicated structure of the liquid filling device often brings about loss of the liquid in the aspirating process and the filling process. Therefore, especially when an expensive liquid is to be filled in the liquid chamber unit, the loss of the liquid has to be minimized as much as possible.